On Friday, the United States and China said they made progress in talks to resolve a nearly 16-month long trade war that has impacted economies across the world, with U.S. officials saying a deal could be signed this month.
Thai stocks jumped nearly 2%, closing at a near 2-week high.
"Last week, the index ended below the 1600-point level. So, there is some buying back into the stocks that is happening, especially in big-cap sectors like banking and electrical," said Teerada Charnyingyong, analyst at Phillip Capital Thailand.
Also aiding sentiment was the expectation of a rate-cut by the Bank of Thailand at its meeting on Wednesday to support growth.
Utilities and materials were among the biggest gainers, with Gulf Energy Development PCL and PTT Global Chemical PCL closing 5.9% and 5.4% higher, respectively.
The Philippine bourse <.PSI> gained 1% to end at its highest in over three months, lifted by financials and utilities firms.
Index heavyweight SM Prime Holdings added 1.3%, rising on upbeat quarterly results, while Manila Electric Co rose 2.5%.
Malaysia's benchmark index <.KLSE> gained 0.6%, shrugging off a worse than expected decline in its September exports.
The country's exports in September fell 6.8% from a year ago, their biggest decline in nearly three years, widening from the previous month's drop of 0.8%, and widely missing a Reuters poll forecast of a 0.1% decline.
Consumer and basic materials firms were among the top gainers, while financials edged lower ahead of the central bank meeting on Tuesday, where it is expected to keep its benchmark rate unchanged, according to a Reuters poll.
Indonesian shares <.JKSE> finished 0.4% lower, posting their third consecutive sessions of loss.
Finance Minister Sri Mulyani Indrawati said that the country's tax collection in the first nine months of 2019 had been hurt by slowing economic activity, and estimated the 2019 fiscal deficit to widen to 2% of gross domestic product.
Financial and consumer sectors were the biggest losers, with Bank Central Asia and Unilever Indonesia losing 0.7% and 1.5%, respectively.
Singapore's Straits Times index <.STI> pared some of the early gains to finish 0.2% higher.
Index heavyweights DBS Group Holdings and Capitaland Ltd were up 1% and 1.1%, respectively.
Vietnam stocks <.VNI> hit their highest in over one year, as financials gained. Bank for Foreign Trade of Vietnam closed at a record high.
(Reporting by Sameer Manekar in Bengaluru; editing by Uttaresh.V)
By Sameer Manekar